Automatic Test Equipment (ATE) is commonly used within the field of electronic chip manufacturing for the purposes of testing electronic components. ATE systems both reduce the amount of time spent on testing devices to ensure that the device functions as designed and serve as a diagnostic tool to determine the presence of faulty components within a given device before it reaches the consumer.
In general, components, for example, electronic components or devices, micro-electronic chips, memory chips or other integrated circuits (IC), are usually tested before they are delivered to a customer. Testing may be performed in order to prove and ensure the correct functional capability of the devices. The tests are usually performed by means of an automated test equipment or test system. Examples for such ATE are the Advantest V93000 SOC for testing system on a chip and system on a package, the V93000 HSM high speed memory tester (HSM) for testing high speed memory devices and the Advantest V5000 series. The first is a platform for testing systems on a chip, systems on a package and high-speed memory devices. The latter is for testing memory devices including flash memory and multi-chip packages at wafer sort and final test.
During testing these devices under test (DUTs) are exposed to various types of stimulus signals from an ATE. The responses from such devices under test are measured, processed and compared to an expected response by the ATE. Testing may be carried out by automated test equipment, which usually performs testing according to a device specific test program or test flow. Such an automatic test system may comprise different drivers for driving certain stimuli to a DUT, in order to stimulate a certain expected response from the device under test. Receiver units of the ATE may analyze the response and generate a desired output regarding the performance of the measured device.
ATE systems can perform a number of test functions on a device under test (DUT) through the use of test signals transmitted to and coming from the DUT. The DUT Interface board is docked to the ATE system by a mechanical system that secures board and makes electrical contact using, for example, a interconnect system of pogo blocks and blind mate RF SMP connectors. An SMP connector offers a frequency range of DC to 40 GHz and is commonly used in miniaturized high frequency coaxial modules. The ATE can interface to and test semiconductor devices in package or wafer form.
Conventional ATE systems are very complex electronic systems and generally include resources such as digitizers, computers, and digital control hardware to analyze the signals from the DUT to the tester system during a session the nearly replicates the real environment envisioned for DUT operation. Test signals transmitted from the DUT at high frequencies are commonly analyzed for the modulation characteristics the DUT are capable of providing. Special features may be incorporated in the design of DUT transmitters that create swept-source or FM (frequency modulated) waveforms that are ramps (up or down) or saw tooth (both symmetrical and non-symmetrical). The FM chirp (a FM ramp waveform that occurs during a specific time-span) along with other FM waveforms is commonly used in radar (radio detection and ranging) applications to mitigate detector bandwidth limits and reduce the cost of the end application like automotive radars. The radar application is used to determine a distance or range from the transmitter to a target, and in automotive applications may also determine speed of the target.
To test the FM chirp signal, typically, high-speed oscilloscopes are used to capture the time domain signal sweeping over frequency. This measurement requires expensive wideband analog hardware, synchronized measurements, and various techniques for the processing (IQ, etc.) to characterize a chirp signal to high accuracy. Thus, this technique does not lend itself to practical ATE or economical methods for determining functionality and nominal performance.
Further, the analysis and characterization of a FM chirp, which is a high speed sweep of frequency over a very short time period (typically on the order of 100 micro-seconds) is a difficult and hardware intensive test because of the challenges involved in simultaneously capturing the swept frequency over the short time periods. Specialized bench equipment, e.g., spectrum analyzers, etc. that may be used are expensive and impractical for test floor applications in high volume testing environments. Further, high performance bench equipment does not lend itself to high volume ATE application work in general because the equipment can be time consuming to use, difficult to set up, require highly experienced and educated test floor technicians or may not integrate well with the ATE hardware. Further, specialized bench equipment such as frequency analyzers occupy a considerable amount of bench space in the testing environment and do not provide a straightforward method for characterizing the FM chirp signal, e.g., specialized bench equipment do not provide a visual indication of the FM chirp.